Recording echo-ranging devices



March 18, 1958 RA. FRYKLUND 2,827,619

RECORDING ECHO-RANGING DEVICES Filed Feb. 27, 1953 s Sheets-Sheet 1 /NIVEN 7-0/2 ROBERT A. FRYKL UND Y T ORNEY March 18, 1958 R. A. FRYKLUND 1 RECORDING ECHOI-RANGING' DEVICES 3 Sheets-Sheet 2 Fi1e d Feb-. 27. 1955 FIG. 3

/NVENTO/2 ROBERT A. FRY/(L UND BY 2%,,

ATTORNEY March 18, 1958 R. A. FRYKLUND RECORDING ECHO-RANGING DEVICES 3 Sheets-Sheet 3 lNVENTO/ PoBEnT A. F'RYKL UND gr RNEY Filed Feb. 27, 1955 RECORDING ECHO-RANGING DEVICES Robert -A. Fryklund, Dedham, Mass., assignor to Raytheon Manufacturing Company-Newton, Mass.,- a corporationof Delaware Application Eebruary..27, 19ss, seriaiNo.s39,429

S-Claims. cram-s This invention. relates to-echo-ranging-devices and more particularly to-an inexpensive reliable type of recorder particularly useful in echo-ranging systems.

It is well known that .a record may be made on sensitized paper by drawing the :paper slowly across a conduetive backing plate and drawing a record-making member, such as a resilient signalp stylus, rapidlyacross the paper substantially at right angles "to the direction of motion of the .papenacross theplate. ,Much diificulty, however, has beenexperienced in obtaining a mechanism for drawing ,the resilient .signal recording member-accurately across the paper. 'In general, previous systems involved theuse of va flexiblecarrier mounted-on pulleys which are driven at a constant speed by-a. mommy-thereby drawing the .stylus member :uniformly acrossthe 1 paper. However, .such arrangements are relatively expensive and are .subjecttofailure by reasonv of .the .flexible member slipping. off thepulleys-or wearing out.

.Thisinvention discloses a, rugged inexpensive mechanism for drawing thestylusacross thepaper at the desired speed and thenlifting the stylus ofl? thepaper and returning itto its startingpoint at .a. relatively greater-speed. Briefly, "this is accomplished, by an arm positioned atright angles to the direction of the :paper, said arm being pivoted on a pair of eccentricallyrotatable pivots carried by-a pair of meshedgears. :One. of thepivotsis fixedzto thearm andthe other of said,pivots .slidably engages a slot in the armfsuchthat rotation of .thegears causes the free end of the. arm, which carriesthe stylus, .to move downwardpastlhepaper alonga substantially straight line and then. move back up .across the ,paper along the substantially arcuate path, ,whichflifts the stylus otf the paper.

This inventionffurther disclosesthat the stylusmay be lifted away from .thepaper, moreefiectively by means of acarn-operated linkage which rocks the stylus member at the end of thearm, the contour of the cambeing designed to lift the stylus awayirom the paper sufiiciently ,at the end of the downward stroke such thatit .will:not,.engage the paperrasrthe. stylus movesback up, thereby eliminating tearing or other damage of the .paper. Thecontour of the cam is alsoshaped. suc'h thatit will compensate for any .non-linearities during the downward stroke of the stylus, thereby causing, thestylus tip ,to movein a straight line and resulting in constant stylus pressure on;the paper.

inventionjfurther discloses that oneo'f the geared members .carryingone of ,the pivots may also. carry a keying, arrangement for controlling the radiation of energy from the system, whereby the starting time of the energy States aterrt from the center cifthegear 22. pivots comprises a screw 23 which slidably engages a slot 24 in arm 'ZQ and .threadedly engages a gear 25, whichisradiation may'be 'synchronizedwith a given position of theisty'lus on theipaper.

.Qther and further advantages of this,invention :will 1 2,827,619 Pitented Mar. 18, 1958 Fig. 2 illustrates a structural diagram of the arm. and stylus shown :in-Fig. '1 for ditferent phases of thecycle;

Fig. .-3 illustrates .a topplanview of the deviceshown in Fig. 1;

Fig; 4 illustrates a front elevation view of'the :device shown in Fig. 1;

Fig. 5 illustrates a further-embodiment of the invention wherein a cam member is not required to lift the stylus off thepaper;

Fig.1.6 illustrates the mechanism of Fig. 5 in a different phase-of the cycle; and

Fig. 7 illustrates-:a diagram-showing the path of travel of.thestylus-carryingrend of the arm.

.Referring'now'to. Fig.;l,-.there is shown a transducer 10 which maybe of any well-known type, such as .a crystal or magnetostrietive transducer, which is periodically pulsed byaenergy from a driver 11, which may be either akeyed oscillator or-a sharp pulse generator, which shcck -excites.-the:transdueer. :The sonic energy generated by the transducer is radiated downward through a medium whose depth is to be measured, such as, for example, a body of water, andechoes reflected from the bottom of the-body or from. objects in the medium are received :by the transducer and fedto a receiver 12, which may constitute several stages 'ofamplification, and, if desired, a detector. The output of the receiver 12 is fed'to an indicator 13, details ofwhich areshown in Figs. 1, 2, 3 'and 4. Theindicator, 1 3 is-of the recording type andhas as the recording medium a sensitized paper 14 which is adapted to be. drawn acrossa metal platen 15 from a storage roll 16.:by meansof a driving roller-17 driven by a motor 1-8, which may be,.for.example,-a small synchronous motor of the type often used in electric'clocks. The driving roller517 moves very slowlyand draws the sensitized. paper 14.across the platen 15 atarelatively low speed,-for example, six or twelveinches an hour. At the end of the'platen adjacent therpaper storage roll 15 'there'is provided a. -linkage=arrangement forrepeatedly drawing a record-making member comprising a flexible wire stylus 19 repeatedly across thepaper l4 substantiallyat right anglest'othe direction of motion thereof. The stylus *1? is drawn downwardacross "thepaper 124 from the upper to the lower edge. thereof in resilient contact with thepaper Hand is then lifted oflithe paper and returned to the upper edge of. the paper to repeat the cycle.

The linkage arrangement, .which carries the 'stylus w, comprises an arm 20, which lies in a plane substantially perpendicular-tome metal platen 15 andmoves'in said plane in a direction perpendicular to the direction of motion of the paper 14. .In order. torproduce the desired motion of the arm.2(l, said arm'is pivoted on a'pair of pivots positioned behind the plane of the platen 15. A first of said pivots comprises a screw 21 extending through a hole attheyother end of the arm 26 from that carrying the stylus '19 and thre'adedly engaging a gear 22 at apoint positionedradially outward by'a predetermined distance The second of said of an inch below the middle thereof, said line extending downwardly at arslightly oblique angle from platen 15 through the centers of gears 25 and 22. The center of gear 25 is positioned approximately two inches from the platen '15 along said line, and the center of gear 22 is positioned an additional two inches away from platen .15 alon said line. For the particular embodiment illustrated in Figs. 1 through 4, the distance of the screw pivot 21 from the center of gear 22 is slightly greater than a quarter of an inch and the distance between the center of gear 25 and the center of pivot screw 23 is slightly greater than eight-tenths of an inch. In order to produce an expanded scale toward the upper edge of the paper 14, the pivot 23 has been advanced with respect to the pivot 21 by approximately one radian; that is, when the pivot 21 lies on the lines intersecting the centers of gears 25 and 22 intermediate said centers, the angle formed by the radius of gear 25 intersecting the center of pivot 23 and the line extending between the centers of the gears 25 and 22 is approximately one radian, with the pivot 23 being advanced by this amount in the direction of rotation of the gear 25.

In order to correct for the motion of the end of arm 20, which is somewhat non-linear during the downward stroke, and to raise the stylus 19 from the paper during the upward stroke, there is provided a cam 26 rigidly attached to gear 22 by means of pivot screw 21. A cam follower 27 is slidably retained by means of grooves, not shown, in slot 24 and engages the peripheral surface of cam 26. Follower 27 is resiliently held against the surface of cam 26 by means of a spring 28, one end of which is connected to a stud on follower 27 and the other end of which is connected to a post 29 which maintains the spring 28 in tension, urging the follower 27 against the cam surface 26. Attached to follower 27 is a rod 30 which extends into the region of the styluscarrying end of arm 20 and is attached by means of a pin 31 to the stylus holder proper 32 which comprises a clamp tightened by a knurled thumb screw 33. The holder 32 is pivotally mounted on arm 20 by means of a pin 34, the distance between pivot pins 31 and 34 being on the order of seven-sixteenths of an inch with pivot pin 31 being below pivot pin 34. As a result, the motion of cam follower 27 causes the stylus holder 32 and hence the stylus 19 to pivot about the pin 34. The contour of cam 26' is out such that, as the stylus 19 is drawn downwardly across the paper, it follows a substantially straight line and thereby exerts a substantially constant pressure on the paper 14. At the end of the downward stroke, the cam 26 is contoured to allow the stylus 19 to be raised off the paper during the return portion of the cycle. It may be noted that, by making the arm 20 and the cam 26 of insulating material and the rod 30 as well as the stylus holder 32, cam follower 27, spring 26 and post 29 of conductive material, the signal output of the receiver 12 may be applied to the stylus 19 by connecting said output to the post 29.

In order to key the driver 11 at a predetermined position of the stylus 19, for example, when the stylus 19 is just contacting the upper edge of the paper 14, there is provided a switch 35 comprising two flexible contacts 36 held in an insulating holder 37 mounted on a frame bracket 38. One of the flexible contacts 36 is connected to ground and the other contact is connected by means of a lead 39 through a switch 40 to the driver 11. An insulating member 50 is rigidly attached to the gear 25 and carries therein a metal bar 41 which produces a contact between the flexible leads 36 at one position of rotation of the gear 25. The particular position of gear 25, at which shorting between the contacts 36 by metal bar 41 occurs, is determined by the normally fixed position of the frame member 38 which may be adjusted by movement thereof about the axis of gear 25.

Another set of keying contacts 42 is provided which is similar to the set of keying contacts 36 and is adapted to be engaged by the metal bar 41 at another position of the gear 25. By switching the switch 40, the set of keying contacts 42 may be substituted for the keying contacts 35 and a diiferent zero produced which allows substantially the first half of the range to go unrecorded while recording the second half of the range on the record paper 14.

The stylus 19 moves somewhat more rapidly downward over the upper half of the paper 14 than over the lower half thereof. As a result, the depth scale is expanded toward the top of the paper where the lesser or shoal depths are recorded and is compressed toward the bottom of the paper where the greater depths are recorded. This type of scale is particularly advantageous in small-boat installations where the shoal depths must be accurately known in order to prevent running the boat aground and the greater depths, while of interest for navigation or fishing purposes, are not as critical and may be compressed, as greater detail is not of importance.

Referring now to Figs. 5, 6 and 7, there is shown another embodiment of the invention wherein a cam arrangement is not required to control the movement of the stylus 19; rather stylus 19 is fixed to the end of the arm 20. The arm is carried by pivots 21 and 23 mounted on gears 22 and 25, respectively, similar to the structure of Figs. 1 through 4, except that the line intersecting the centers of gears 22 and 25 is positioned substantially at right angles to the plane of the platen 15. The dimensions of the gears and the distance of the gears from the platen 15 as well as the eccentricity of the pivots are substantially the same as that shown in Fig. 1.

Fig. 5 illustrates the mechanism as the stylus is being drawn downward in contact with the paper 14. Fig. 6

, illustrates the mechanism just before the stylus contacts the paper, while Fig. 7 illustrates diagrammatically the path of a point on the arm 20 which is substantially the same distance from the pivot points as the tip of the stylus 19 which contacts the paper 14. The path runs from its uppermost point 43 downward along the substantially straight line 44 to its lowermost point 45, following which it returns to point 43 along an arcuate path 46. It may be noted that, for this to occur, the pivots 21 and 23 are in phase; that is, both pivots cross the line between the centers of the gears 22 and 25 at the same time. The center of the platen 15 is displaced above the line 44 by an amount on the same order of magnitude as the length of the stylus 19, such that the stylus tip will follow a path substantially similar to that described, drawing the stylus down across the paper on the platen and returning the stylus to its upper position with the stylus removed from the paper due to the arcuate path 46. The width of the platen and paper is made somewhat shorter than the length of the straight line 44 such that the stylus starts its straight line excursion from a point above the platen and paper, and finishes its straight line excursion at a point somewhat below the platen and paper, thereby allowing sutficient room forthe stylus to lift away from the paper during its return to the top of the paper without catching and tearing the bottom of the paper. As the gears 22 and 25 rotate at constant speed, the stylus moves downward across the paper at a substantially linear speed for the dimensions given with a very slight sinusoidal distortion in linear velocity.

This completes the description of the embodiments of the invention illustrated herein. However, many modifications thereof will be apparent to persons skilled in the art without departing from the spirit or scope of this invention. For example, the species of Figs. 5, 6 or 7 can use either of the keying arrangements illustrated in Figs. 1 through 4. The recorder, while primarily useful with depth sounding apparatus, may be used for other purposes, such as range or other time sequential recording functions, and the dimensions given may be varied to produce different degrees of linearity and stylus velocity. Accordingly, it is desired that this invention be not limited by the particular details of the embodiments disclosed herein except as defined by the appended claims.

What is claimed is:

1. An indicator system comprising a record medium and a record-making member, means to draw said recordmaking member across said medium comprising an arm,

an eccentrically continuously rotatable pivot fixed to said arm, an eccentrically rotatable pivot slidable along said arm, means for synchronizing the rotation of said pivots comprising a pair of meshed gears, and means for eccentn'cally mounting one of said pivots on each of said gears.

2. An indicator system comprising a record medium and a record-making member, means to draw said recordmaking member across said medium comprising an arm, an eccentrically continuously rotatable pivot fixed to said arm, an eccentrically rotatable pivot slidable along said arm, means for synchronizing the rotation of said pivots comprising a pair of meshed gears, means for eccentrically mounting one of said pivots on each of said gears, and means for moving said medium substantially at right angles to said arm.

3. An indicator system comprising a recording medium and a record-making member, means to draw said recordmaking member across said medium comprising an arm, an eccentrically continuously rotatable pivot slidable along said arm, and means for urging said record-making member toward said medium as said member is drawn across said medium in one direction and for urging said member away from said medium as said member is drawn across said medium in the opposite direction comprising a cam attached to said fixed pivot, 21 second eccentrically continuously rotatable pivot slidable along said arm and said arm, means for synchronizing the rotation of said pivots comprising means for mounting said pivots on a pair of meshed gears, and a mechanism for moving said medium substantially at right angles to said arm.

5. An echo-ranging system comprising means for radiating energy and receiving reflected echo energy, and an indicator energized by said received echo energy comprising a recording medium, and a record-making member, means for drawing said member across said medium comprising an arm, means for pivotally mounting said arm on an eccentrically rotatable pivot fixed to said arm and on an eccentn'cally rotatable pivot slidable along said arm, and means for urging said record-making member toward said medium as said member is drawn across said medium in one direction and for urging said member away from said medium as said member is drawn across said medium in the opposite direction comprising a cam attached to said fixed pivot, a second eccentrically continuously rotatable pivot slidable along said arm and a link joining said record-making member and said second rotatable pivot.

References Cited in the file of this patent UNITED STATES PATENTS 287,685 Jones Oct. 30, 1883 1,869,909 Norwood Aug. 2, 1932 2,355,502 Barton Aug. 8, 1944 2,395,658 Disney Feb. 26, 1946 2,406,861 Springer Sept. 3, 1946 2,442,586 Clark June 1, 1948 2,491,020 Winchel Dec. 13, 1949 FOREIGN PATENTS 534,095 Germany Sept. 23, 1931 

